Study casts doubt on benefits of organic produce

(GETTY)

Organic produce is no more nutritious than conventional alternatives, according to new research, which has cast doubt on organic food's healthy-eating credentials.

A study by scientists at Stanford University which compared organic and conventional foods found no strong evidence that eating organic had health benefits over conventional produce. The findings come as a separate study, at Oxford University, suggested some organic farming methods could more cause more harm to the environment than conventional agriculture.

The studies make worrying reading for an industry that markets itself as the ethical choice for environmentally-aware, clean-living consumers.

Researchers at Stanford looked at 240 studies of nutrient levels in food and nutrition levels in humans.

"Our comprehensive review of the published literature on the comparative health outcomes, nutrition, and safety of organic and conventional foods identified limited evidence for the superiority of organic foods," the report, published in the US journal Annals of Internal Medicine, states. "Despite the widespread perception that organically produced foods are more nutritious than conventional alternatives, we did not find robust evidence to support the perception."

The Oxford study, meanwhile, found organic milk, cereals and pork all generated higher greenhouse gas emissions per unit of production than conventionally-farmed counterparts. Dr Hanna Tuomisto, who led the research at the university's Wildlife Conservation Research Unit, said the label "organic" was not a guarantee of the most environmentally-friendly product. "While some organic farming practices do have less environmental impact than conventional ones, the published evidence suggests others are actually worse for some aspects of the environment," she said.

But Lord Peter Melchett, policy director at the Soil Association, said the study was "extremely misleading" and that measuring environmental impact per unit of product could skew the result, as yields on organic crops and products were usually lower.

One health benefit that scientists at Stanford did find, was that eating organic foods can reduce the risk of exposure to pesticide residue.